A = readmatrix ('-10Vcool.csv')

x = A(:,1)
y1 = A(1:57,3)
y2 = A(58:72,3)/12
y = cat(1,y1,y2)

z1 = A(1:57,5)
z2 = A(58:72,5)/12
z = cat(1,z1,z2)

r = (z-y)./(abs(z)+abs(y))

plot(x,r,LineWidth=1,Color=[0 0 0])